We ar proposing to conduct a case-control study to test the hypothesis that infection with a sexually-transmitted virus is related to an increased risk of vulvar cancer. The study will be conducted in three counties of western Washington. Female residents who are diagnosed with invasive or in situ vulvar cancer during January 1980 - December 1985 will be identified and interviewed regarding history of sexually-transmitted diseases. Tissue samples will be examined using in situ hybridization to determine whether neoplastic cells in vulvar carcinoma contain any viral genes or gene products. The presence of human virus antigen will be determined by immunoperoxidase. Blood samples will be collected for all cases and analyzed for evidence of prior exposure to sexually-transmitted viral infections. On the basis of prior evidence, our main emphasis will be placed on the human papilloma virus; however, indicators of past exposure to other sexually-transmitted viruses and pathogens will also be assessed. Similar interview data and specimens will be obtained from our control group - women surgically treated for benign pigmented nevi. This control group will be matched to the cases on the basis of age, race, and county of residence.